Small-sized synchronous motor with specific stator coil length to stator coil radius ratios

Abstract

A small synchronous motor is provided with a stator winding wound around a stator core. Conversion efficiency is improved by setting the ratio of the coil length (L) to the thickness between the center of the core and the outer most periphery of the coil (R) to be L/R to 40.

What is claimed is: 
     
       1. A small-sized synchronous motor including: a stator having spaced-apart magnetic poles and being magnetically connected to both sides of a core around which is wound a coil, and a rotor rotatably disposed between the magnetic poles of said stator, wherein the length L of said core around which said coil is wound and the thickness R between the center of said core and the outermost periphery of said coil satisfy the relation 10≦L/R≦40. 
     
     
       2. A small-sized synchronous motor according to claim 1, wherein the length L of said core around which said coil is wound is 30 mm or more.